1. Field of the Invention
The present invention relates to the concurrent capture and demodulation of a full region of spectrum of selectable radio frequencies typically containing audio and communication signals for time shifting, random access of individual channels or time frames, digital recording and advanced content management.
2. Description of Related Art
Currently, state of the art audio systems provide live playback of audio broadcast signals. These audio systems accept a wide-band signal and selectively demodulate a single channel of the broadcast audio spectrum for playback. For example, a frequency modulated (“FM”) stereo tuner receives a radio frequency band described as the FM band. In the United States, this band includes radio frequency energy from 87 MHz to 108 MHz, which includes approximately 100 channels separated by 200 kHz. A listener can adjust the FM tuner to receive any one of the channels of audio signals for playback at one time. For instance, the listener may adjust his FM tuner to receive 88.1 MHz., or 88.3 MHz. The FM tuner will then demodulate the base-band audio signal present at 88.1 MHz., and allow the listener to hear the live audio broadcast present at that frequency.
Many of these channels provide news, weather or traffic information broadcasts that are helpful to listeners. For instance, a listener may hear a traffic information broadcast while driving to work. The broadcast allows the listener to modify his driving route to minimize travel delays due to traffic. Similarly, weather broadcasts allow listeners to adjust their activities according to the current or forecast weather. Finally, listeners can hear news broadcast to stay informed of current events.
Additionally, some radio stations broadcast data along with the audio. This data can be extracted and stored by certain state of the art systems and used to display textual information relating to the content of the audio broadcast. This textual information may provide the identity of a broadcast, advertising information, or other pertinent information about the broadcast. This information can be used in a variety of ways by existing systems.
However, a problem with state of the art audio systems is that such systems require listeners to adjust the audio system tuner to the station at the time the broadcast is occurring. Moreover, they must listen to the broadcast as it occurs. For example, if the listener has adjusted his tuner to channel A, and the traffic report is occurring on channel B, the listener will miss the traffic report completely. Another problem with such systems is that if the listener is not listening to the broadcast, no practical method exists for accessing the missed broadcast for later playback. For example, if the listener turns on his state of the art audio system at 8:00 AM, but the traffic broadcast occurred at 7:50 AM, the listener will have completely missed the traffic broadcast. Yet another problem with such systems is that if the listener hears the end of a news broadcast and wishes to hear a missed portion, no method exists for replaying the missed portion. Moreover, if the listener becomes interrupted while listening to an audio broadcast, the listener cannot simply replay the broadcast.
At present, the state of the art audio systems are capable of recording communications broadcasts. However, a problem with such systems is that a communications system with one tuner can only record one communications channel at any one time. With such systems a listener must determine in advance what channel to record. Moreover, the listener would have to set the system to record a particular channel in advance of the broadcast. These requirements make the state of the art audio systems impractical for random access of audio broadcasts on multiple channels, past and present.
If, however, a method existed to automatically receive and store the communication broadcast, the listener could playback portions of broadcast that were missed. Similarly, if multiple channels could be received and stored simultaneously, the listener would not need to be concerned with tuning to a particular communications channel. Further, if the listener is interrupted, the listener could pause the broadcast and resume listening later without missing any portion of the broadcast. Additionally, a user could randomly select any broadcast for playback from the group of broadcasts occurring presently or in the past, subject to practical memory considerations.
Therefore, a need exists for listeners to be able to randomly access broadcasts that have already occurred or are occurring. There is a need for a system for capturing multiple communications channels simultaneously, storing such channels individually, and allowing random access and manipulation of such signals at later times.